1. Field of the Invention
This invention relates to an assembly for the removal or recovery of petroleum oils, fats, greases, lipids or like liquid of the type found in the drains or effluent discharge of restaurants, food processing or like facilities, industrial plants, maintenance facilities or other circumstance involving mixtures of aqueous liquid and the material to be removed or recovered.
2. Description of the Prior Art
Oil and grease contaminant removal or recovery systems are well known in the prior art. It is desirable in modern day plumbing facilities to remove as much of the collected oil and grease from drain water as possible in order to alleviate any clogging difficulties with conventional plumbing or sewage systems to which the drain water is ultimately directed and to reduce the load to be processed by sewage treatment facilities.
One method recognized in the prior art of accomplishing such removal is the use of one or more rotating disks formed of a plastic or like applicable material to which oil and grease contaminants are attracted. Typically, the rotation of the disk in an at least partially immersed condition allows the oil to cling to one or both sides of the disk so the contaminants are removed from the body of water upon rotation of the disk. A scraper is typically used to force the oil contaminants from the opposite sides of the disk and channel such contaminants, once removed, to a collection or disposal facility.
The following U.S. Patents are representative of such oil, grease and like contaminant removal structures.
U.S. Pat. No. 1,860,819 to Schamberger discloses an apparatus for removal of oil from water by the use of rotating cylinders such that the oil is picked up by the circumferential sides of the cylinders and scraped therefrom.
U.S. Pat. No. 3,905,902 to Hoegberg et al. discloses a recovery system for oil and oil soluble contaminants using a negatively electrostatically charged hydrophobic rotating disk immersed in the water to be cleaned. Wiper blades bear against opposite sides of the disk in order to remove oil contaminants. Such contaminants are conveyed away to a storage facility. The wiper of this invention is pressed physically against the rim of the disk with considerable force so as to frictionally bear against the disk and produce a static charge by triboelectric effect. To do this and produce a negative electrostatic charge is important to the stated invention. Contact with the disk for the removal of the oil is accomplished by a bifurcated wiper member arranged at an angular orientation for the channeling of the collected oil therefrom and further wherein the disk or the disks utilized are electrostatically isolated from grounded conductors in contact with the water.
U.S. Pat. No. 4,051,024 to Lowe et al. discloses an oil recovery apparatus and method including a plurality of disks carried on a rotatable shaft partially immersed in the fluid to be cleaned. Opposite sides of the disks are scraped by scraping blades arranged at a particular orientation by means of a channeled holder of such blades which is angularly oriented to facilitate removal of the collected contaminants by gravity.
U.S. Pat. No. 4,268,369 to Lowe discloses an oil recovery apparatus and method particularly for removing oil and grease from the discharge of dishwashing machines and the like and employs a single rotating disk of plastic or like material engaging a pair of spaced apart scraper blades arranged to scrape opposite side of the rotating blade. The blades are mounted on a removable bridge member extending above a high point of the disk and depend downwardly therefrom in substantially transverse relation to the surface of the body of water being cleaned. A discharge conduit is disposed in direct fluid communication with one of the blades for the removal of the collected contaminants to a collection or disposal facility.
Similarly, U.S. Pat. No. 4,651,762 to Bowden discloses an agitation parts degreaser also incorporating as a part thereof a rotating disk made of appropriate material to which oil contaminants are collected and further incorporating a pair of spaced apart scraper blades engaging opposite sides of the disk for removal and disposal of the contaminants collected from such opposite sides during continuous rotation of the disk.
U.S. Pat. No. 4,235,726 to Shimko, assigned to the assignee of the present application, discloses an automatic grease separating apparatus in which a curved plate reciprocates into and out of the contaminated water, with scrapers aligned to scrape grease and oil from the plate on its trip out of the water.
The above-mentioned devices are assembled with rigid mounting means to position the scraper drive mechanism and oil/grease discharge chute. This makes servicing of the apparatus exceedingly difficult, particularly since the parts to be serviced have been covered in grease or oil. The likelihood that bolts or other parts will be dropped by servicemen is very high in these circumstances, and the location to which the dropped part falls--submerged in waste water--is a very unpleasant location from which to retrieve the lost part. In addition, since the units are usually permanently installed in a plumbing system, field service is required and the prior designs have not accommodated themselves to such service.
Accordingly, there is a need in the art for a new apparatus for separation of oil/grease from wastewater which is simple in design so that service is not often needed, yet capable of being done in the field by simple replacement of easily replaceable parts.